Pencils, particularly conventional pencils but also some types of mechanical pencils, need sharpen to write sharply and neatly. Before the development of dedicated pencil sharpeners, a pencil was sharpened by whittling it with a knife. Pencil sharpeners made this task much easier and gave a more uniform result than a knife. A pencil sharpener sharpens a pencil's writing point by shaving away its surface.
The first American pencil sharpener was patented by Walter K. Foster of Bangor, Me. in 1855. They now come in a wide array of colors and shapes.
Manual sharpeners have no moving parts and consist of a combined point-shaping cone that is aligned to the cylindrical pencil alignment guide hole, into which the pencil is inserted. A sharp blade is mounted so that its sharp edge just enters the shaping cone. The pencil is inserted into the sharpener and rotated while the sharpener is held motionless. The body of the sharpener is often contoured, ridged or grooved to make the small block easier to firmly grip.
The blade inside the sharpener shaves the wood and tip of the pencil, while the shavings emerge through a slot along the blade edge. It may be important that the cylindrical alignment hole closely fit the diameter of the pencil to keep the pencil from wobbling; causing stepped or lurching cut-depths and point breakage.
Conventionally, pencil sharpeners were independent of the pencil, requiring users to search for sharpeners when a pencil needs sharpening. This may be inconvenient. In addition, used pencils reaching certain lengths were considered unusable for being too short and became discarded. This is wasteful. The present invention integrates a pencil sharpener and a writing device such as a pencil so as to increase convenience for the users and reduce waste by utilizing portions of pencils that were thought to be unusable.